This is the number 1 BJJ related question  Nick Albin gest from white belts in the beginning. Because they lack the skills to be effective. They spend a lot of time in bad positions like side control and mount.

So in this video  Nick Albin gives 4 tips that can a white belt in Brazilian jiu jitsu (or anyone really) can use to improve at escaping bad positions.

The tips are (starting with simplest to more in-depth)
– Learn to take a deep breath when you find yourself in bad positions during BJJ rolling.
-Focus on using the Brazilian Jiu-jitsu techniques you’ve learned rather than just pushing and shoving with no rhyme or reason.
-If open mat or extra free mat time is available. Had a partner attack you in your worst position.
-If time is not available or just another way to do it. Find someone you can beat and let them put you in the worst positions possible